Hot air furnace type drying apparatus



D. W. JOHNSTON HOT AIR FURNACE TYPE DRYING APPARATUS Jan. 1957 4 Sheets-Sheet 1 Filed April 9, 1953 INVENTOR.

DANAL w. JIOHNSTON BWyM AT TORN EYS D. W. JOHNSTON HOT AIR FURNACE TYPE DRYING APPARATUS Jan. 8, 1957 4 Sheets-Sheet 2 Filed April 9, 1953 FIG-4 INVENTOR. DANAL W. JOHNSTON BYfi M -1 7 ATTORNEYS Jan. 8, 1957 D. w. JOHNSTON HOT AIR FURNACE TYPE DRYING APPARATUS 4 Sheets-Sheet 3 Filed April 9, 1953 DANAL W. JOHNSTON mgfwq s w ATTORNEYS Jan. 8, 1957 D. w. JOHNSTON HOT AIR FURNACE TYPE DRY NG APPARATUS 'Filed April 9, 1955 4 Sheets-Sheet 4 IN VEN TOR.

N S m a N N wim J4 w: M N MW United States Patent H011 AIRFURNACE T-YPELDRYING APPARATUS D'analwW; Jblmstoms PiquapOhio, assignor to Hart'zell Industries; Inc-,Jfiqua,,flhiaaarcorporatinn of Ohio.

A'pplication'Aprilfii, 1953, Serial No. 347,659'

6:Cl'aims. (C12 126-110) This: inventiorrrrelatesa to a drying apparatus, and is a continuation-impart: of.- rny co-pendingr application; Serial Nm, 2516;191, tfiled. November: 14', 19:51; now'Patent No. Z,7z16;975.; .datedtseptemberad, 1955*; and assignedr to the same-:assignee. as'the: instant application.

'Dhisdnvention-is particularly! concerned with a" drying apparatus which: is; portable and which is especially adaptedfor: the drying oft farm crops" andithe: like.

Many farm; crops areiadv-antageously drie'dibefore being marketed, processed or stored, suchlcrop'slincluding grain crnps',.par1icularly corn;v soy= beans, rice, etc.- and most forage crops. vegetablesamay-also be:dried with-thedrier of the present invention;. and in. all cases the advantages: obtain of a high speed of drying with the drying conditions= being widen-control .at i all; times;

The present inventionhas as aprimary-object'theprovisionoffanimproved burner head in use for connection with: a; drying arrangement" characterized byan angular constructionzwhichdends itself tobeing incorporated in the generally tubular drier structure.

Another 'objectzis' an' improved construction of the drier, by meanso'f whichla burner chamber 'is' supported within an air-duct so'thatt expansion or contractionofth'e burner chamber does-not impose stresseson-theframe of the d'ri'erz.

Aastillifurther object is the provision of a drier structure of the: nature referred. to in which there is an ex? tremely efficient transfer of' heat between the burner chamber and the air passingthrough the drier'while at the same 'timethe passage of'the air through the drier issubstantially: unimpeded whereby greater volumes of heated: air are-available for drying purposes;

Another object of the present: invention is the provision of' a: drying arrangementbhaving a fan for'blowing air throughathe= drier in which the' incomingcool air isso guided and directed that it forms a blanket over the hottest'portionsof the drier, thereby making thed'rier safer: to useunder all'circumstanees.

These and other objects and advantages willbecom'e moreiapparent upon refereneeto the following "specificationltaken in connection with the aecompanying-drawings, in which:

Figure 1'is-a-=side'view of a drier constructed according to this invention" partly broken away to-show-'- the com struction of the various -elem'ents-thereof Figure 2 is anrend elevational viewlooking in at the discharge. endzof; the: drier and which istherlefttend dn Figure 1;

Figure 3is a sectional iview indicatediby line- 3-3 on Figure 1 showing-more or 'less in detail the internal construction of the drier; t

Figure 4- is a fragmentary sectional view'indicatedvby line 41--4 on Figure 2 showing,theconfiguration andarrangement of an air guide fi-n within the drier;

Figure 5'is a partial'sectional'view showingthe novel construction of the. burner which suppliesheat for the drier; and

Other crops such as tobacco, fruits and v Patented Jan. 8, 1957 Figurcdis'a view similar to FigureS' but showinga modified construction of" the burner.

Referringtothe drawings somewhat more in detail, the drier of thi's' invention comprises a frame which maybe made up of channel-shaped side members 10- suitably rigidly'interconnected to form a unit and" mounted on an axle structure 12 having supporting wheels 14.

At one end of the frame unit there is a clevis' or yoke 15 by means-of-which the driercan'be attached to a tra'c' tor; This same'end of" the-supporting frame also preferably includes an adjustable pedestal member 18" for supporting the framewhen it is disconnected from the'tract'or.

The drier proper includesamain cylindrical outer shell 20' supported on the frame of the drier and within which there is centrally located; in co-axial relation'therewith; a cylindrical heating chamber or cartridge 22' closed" at both ends, and"within which there is'-a burner means" that provides a flarne that generates the heat for the unit.

The cartridge 22' is advantageously supported within shell 20 by means of a sta'cl'orexhaust connection 21 at the right end of the cartridge as-it is' viewed in Figure l, and extending downwardly from the bottom of the carrridge':22i to shell 20. As will be seen by the dotted outline: of the stack in' Figure 3, thismernber is streamlined in-cr0ss=secti0n soastopresent a minimum resistanc'e. to? airflow through" sh'ell'20 toward theleft as it is viewed in Figures 1 and 3.

The outer surface of cartridge 22,- as well as the outer surfaceof stack 21; preferably include the radially projectingafinsZ-S? which may" advantageously take the form of relativelysm'all segmentsisecured to the surfaces on which they are mounted as bywelding; These -fins'- are solely) forz'thei'purpose: of .enhancing'the extraction of heat from: the: cartridge. and the stack.

At the right: end:ofshelll20;=as it is viewed in Figures 1 and:3,tit=iis abutt'ed: bysan: orifice ring: 28in the' inlet of whichthere is disposed a propeller ortfan' 30 carried on the end" of" the: output shaft 32 of a motor" 34 that is mounted on a platform inzazspider-likeframe' 36 h'avin'g the outwardly extending legs 38 which may be'fix'ed' about the periphery of orifice: ring 28 by any'suitablemean's.

-It -will.-be understood' thatthefan or propeller co'uld be of any; suitable type: for propelling the required volume ofrairaxially through shell 20, andthat it could besa'rranged for being driven by an internal combustion engine ratherthanby' the electric motor referred to if desired,iand that it could bedirect driven as illustrated; ordrivenzby-a beltfrom any desired power source.

A suitable screen shield- 40-may beprovided which prevents foreign matter from getting into the air stream being blown, and likewise provides a protective shield about vthe fan to preventpe'rsonnel injury.

Surrounding the right end of shell 20 and extending fromnthezouter edge of orifice ring 28 toward the opposite end of the unit is an outer: shell member 50 which has its left end-in Figure 1- connected-with the 'outer' periphery of shell 20 as-by the angle meansat 52. It will bemoted that-shells 20tan'd 50 form an annularchamber that communicates with-the-lower open end of stack 21'. This:chamber serves totconduct'exhaust gases from stack 21 toiscreened exhauststack 54 atthe top of the unit.

Spaced about outer shell 50-is a sheet 56 extending outer shell 50 by means of the spaced rib members which will be seen at 62 in Figure 2.

In the center at the bottom outer shell 50 is provided with an aperture 64 opening into a small chamber 66 closed by the detachable cover 68. This arrangement provides a ready means for cleaning soot and the like from the combustion chamber so that the drier can be maintained in efficient operation ,at all times.

The end of cartridge 22, opposite fan 30, is provided with a head 70 having a central aperture into which the discharge end of a burner head 72 extends. Burner head 72, according to the present invention and as will be seen in Figures 2 and 3, is of angular construction, and extending radially from the portion of the burner that projects through head 70 is a branch 74 extending through the side of shell 20 for connection with the motor operated pump and blower unit 76 and which may be, in itself, of conventional construction and provided with conventional controls,

The exact nature of burner 72 will be more clearly seen in Figure 5. In Figure there is a conduit 78 through which oil is supplied under pressure to a conduit 80 leading to the twin nozzles 82 that discharge through the ring 84 into the interior of cartridge 22.

Igniter means in the form of electrode prongs 86 are supported in the proper position for igniting the fuel which is discharged from the nozzles as by means of the ceramic support 88 and to which are connected high tension leads 90 that extend from the ignition transformer of the burner unit.

The nozzle end of the burner has a supporting spider 92, while at its other end there is a rod 94 extending adjustably through head 96, and by means of which rod the nozzles 82 can be located in the proper position to insure efiicient combustion.

A deflector member 95 mounted on rod 94 provides means for deflecting the blown air around the corner that connects the burner head with the branch 74. This arrangement promotes efficient operation of the burner.

The burner unit 76 also supplies combustion air which passes through branch 74, and then to the right about nozzles 82 and into cartridge 22.

The modified construction of the burner illustrated in Figure 6 is substantially identical with that shown in Figure 5, except that the Figure 6 modification only comprises a single nozzle. The supporting means for supporting the burners at the end of cartridge 22 is illustrated in Figure 6 wherein it will be seen to comprise a first mounting ring 100 secured to the end of the cartridge and have a substantial clearance about the burner head. A second ring 102 closely embraces the burner head and is bolted to mounting ring 100 by bolts 104. Packing means at 106 between the mounting rings completes the supporting structure for the burner head. The V described arrangement is such that there can be substantial relative expansion and contraction between the burner head and the cartridge without undue strains being imposed on either thereof.

In Figures 1 through 4 it will be noted that inside shell at the entrance end thereof there are disposed a plurality of air guide vanes 110 which, as will be seen in Figure 4, commence spirally of shell 20 and terminate axially thereof. The purpose of the vanes 110 is to straighten out the airflow from propeller and to remove any rotational component therefrom so that the airflow through shell 20 is substantially all in the straight axial direction. This promotes efficient operation of the drier and reduces undesired turbulence and spin in the airstream issuing from the discharge end thereof A further device, according to this invention, for promoting eficient operation thereof takes the form of a deflector member 112, as best seen in Figures 1 and 2, which is located within the cartridge 22 on the burner side of the inlet of stack 21, and which causes the blast from the burner to be deflected in the manner indicated by the arrows 114 in Figure 1. This brings the blast into contact with the entire inner surface of cartridge 22 thereby providing for efficient extraction of heat from the combustion gases from the burner.

In order to assist in supporting the cartridge 22, there is preferably provided a strap 116 extending upwardly from shell 20 to the bottom of the cartridge, as illustrated in Figures 1 and 2. Normally, the stack 21 will support cartridge 22 in its proper location, but strap 116 will provide additional support for the cartridge that is desirable, particularly in view of the portable nature of the drier unit.

It will be understood that suitable controls are provided for starting and stopping the propeller that drives air through the unit and for controlling the operation of the burner, and that such control means would include thermostats and safety controls. These controls have been illustrated, more or less, diagrammaically as being located within a covering hood 118 on the side of shell 20 at the discharge end of the unit. Since these controls are substantially conventional, however, no detailed description thereof is included herein. It will be understood, however, that the controls would include temperature regulating elements, high limit controls, stack controls, and no-fiame controls, which last-mentioned might take the form of the electric eye 97.

It will be appreciated that fuel oil is only representative of the many fuels that could be used in the device of this invention; for example, natural gas, producer gas, L. P. gas, and liquid fuels such as kerosene and gasoline can also be used if convenient.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions, and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

I claim:

1. In a drier unit of the nature described; a horizontal outer shell open at both ends, a fan at one end of the outer shell to drive air therethrough, an inner shell closed at both ends mounted on the axis of said outer shell, an angular conduit having one portion extending radially through the wall of said outer shell and another portion extending axially into said inner shell at the end opposite said fan, a burner within said conduit at the end opening into said inner shell, an exhaust chamber formed around said outer shell adjacent the fan end thereof with the outer shell forming the inner wall of the chamber, said chamber terminating in an exhaust outlet at the top of the chamber at the end thereof opposite the fan, and a stack connecting the bottom of the inner shell at the fan end thereof with said chamber at the bottom thereof, said inner shell and said stack being provided with segmented fins extending therefrom in planes parallel with the direction of airflow through said outer shell.

2. In a drier unit of the nature described; a horizontal outer shell open at both ends, a fan at one end of the outer shell to drive air therethrough, an inner shell closed at both ends mounted on the axis of said outer shell, an angular conduit having one portion extending radially through the wall of said outer shell and another portion extending axially into said inner shell at the end opposite said fan, a burner within said conduit at the end opening into said inner shell, an exhaust chamber formed around said outer shell adjacent the fan end thereof with the outer shell forming the inner wall of the chamber, said chamber terminating in an exhaust outlet at the top, and a stack connecting the bottom of the inner shell at the fan end thereof with said chamber at the bottom thereof, said inner shell and said stack being provided with segmented fins extending therefrom in planes parallel with the direction of airflow through said outer shell, and said stack being streamlined in configuration in horizontal crosssection.

3. In a drier unit of the nature described; a horizontal outer shell open at both ends, a fan at one end of the outer shell to drive air therethrough, an inner shell closed at both ends mounted on the axis of said outer shell, an angular conduit having one portion extending radially through the wall of said outer shell and another portion extending axially into said inner shell at the end opposite said fan, a burner within said conduit at the end opening into said inner shell, an exhaust chamber formed about said outer shell adjacent the fan end thereof with the outer shell forming the inner wall of the chamber, said chamber terminating in an exhaust outlet at the top, and a stack connecting the bottom of the inner shell at the fan end thereof with said chamber at the bottom thereof, said inner shell being provided with a deflector member extending upwardly at an angle from the bottom wall thereof between the burner and said stack serving to deflect the products of combustion upwardly in said inner shell before they enter said stack.

4. In a drier unit of the nature described; a horizontal outer shell open at both ends, a fan at one end of the outer shell to drive air therethrough, an inner shell closed at both ends mounted on the axis of said outer shell, an angular conduit having one portion extending radially through the wall of said outer shell and another portion extending axially into said inner shell at the end opposite said fan, a burner within said conduit at the end opening into said inner shell, an exhaust chamber formed around said outer shell adjacent the fan end thereof with the outer shell forming the inner wall of the chamber, said chamber terminating in an exhaust outlet at the top, and a stack connecting the bottom of the inner shell at the fan end thereof with said chamber at the bottom thereof, said outer shell being provided with guide vanes extending inwardly therefrom at the fan end thereof and comprising spiral portions adjacent the fan and axial portions extending therefrom whereby spin is removed from the blown air.

5. In a drier unit of the nature described; a horizontal outer shell open at both ends, a fan at one end of the outer shell to drive air therethrough, an inner shell closed at both ends mounted on the axis of said outer shell, an angular conduit having one portion extending radially through the wall of said outer shell and another portion extending axially into said inner shell at the end opposite said fan, a burner within said conduit at the end opening into said inner shell, an exhaust chamber formed around said outer shell adjacent the fan end thereof with the outer shell forming the inner wall of the chamber, said chamber terminating in an exhaust outlet at the top, and a stack connecting the bottom of the inner shell at the fan end thereof with said chamber at the bottom thereof, the fan end of said outer shell being flared outwardly in the form of a venturi ring whereby operation of the fan will cause a sub-atmospheric pressure to exist about the periphery of said venturi ring, and a shroud sheet extending about and radially spaced from the outer wall of said exhaust chamber and extending axially to beyond the outer periphery of said venturi ring whereby air will be drawn through the space between said shroud sheet and the outer wall of the chamber by operation of said fan thereby preheating at least a portion of the air blown by the fan and also providing a cooling blanket about said exhaust chamber.

6. In combination in a drier, an outer shell and an inner shell mounted on the axis of said inner shell, a burner head in one end of said inner shell on the axis thereof, a supply conduit extending axially from said burner head and then at right angles through the side wall of said outer shell, the end of said inner shell being formed with an aperture for receiving said burner head with clearance, a flange on said shell also having clearance about said burner head, a flange fixed to said burner head axially spaced from the flange on the shell, packing between said flanges, and bolts connecting said flanges.

References Cited in the file of this patent UNITED STATES PATENTS 1,398,264 Harter a- Nov. 29, 1921 1,558,848 Doble Oct. 27, 1925 1,789,977 Hopkins Jan. 27, 1931 1,839,527 Bates Jan. 5, 1932 1,993,158 Funk Mar. 5, 1935 2,383,431 Weyenberg Aug. 21, 1945 2,386,746 Hess Oct. 9, 1945 2,417,315 McCollum Mar. 11, 1947 2,517,446 Ryder Aug. 1, 1.950 2,579,507 McCracken Dec. 25. 1951 

